Multiplex telephony



(No Model.) 4 Sheets-Sheet 1.

W. W. JACQUES. MULTIPLEX TELEPHONY.

No. 518,367. Patented Apr. 17, 1894.

WITN ESiS/ES. INVENTEJFL f/M Q? ml wmomu. muoanu-nma co'uuuv vusumaron.u. c.

(,No Model.) 4 Sheets-Sheet 2.

W. W. JACQUES. MULTIPLEX TELIEIPHOITY.

No. 518,367. Patented Apr 17,1894.

Fig.4.

Fig. 5. [J WITNESSES. INVENTEIR.

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(No Model.) 7 v 4 Sheets-Sheet 3.

W. W. JACQUES.

I MULTIPLEX TELEPHONY. No. 518,367 Patented Apr. 17,1894.

WITNESSES. INVENTEIFK.

(No Model.) I 4 Shet-Sheet 4.

- W. W. JACQUES.

- MULTIPLBX TELEPHONY. No. 518,367. Patented Apr. 17,1894.

Fig. 7. \IVITNEESEE. INVENTU Fk.

, NITED STATES PATENT OFFICE.

WILLIAM W. JACQUES, on NEWTON, ASSIGNOR TO THE AMERICAN BELL TELEPHONECOMPANY,

OF BOSTON, MASSACHUSETTS.

MULTIPLEX TELEPHONY.

SPECIFICATION forming part of Letters Patent N 0. 518,367, dated April17, 1894. pp c ti filed November 22, 1893. Serial No. 491,675. (Nomodel.)

To all whom it may concern:

Be it known that 1, WILLIAM W. JACQUES, of Newton,in the State ofMassachusetts, have invented an Improvement in Multiple Telephony, ofwhich the following is a specification.

It is a well known fact in physiological acoustics that a-sonnd fallingupon the human ear for a minute fraction of a second,

for example one one-hundred-and-fifty-thousandth of a second, will beaudible, while the ear will utterly fail to detect aninterruption for afar greater interval, for example only one one-hundredth of a second, ina I 5 sound continuous but for said interruption. It follows from thisthat if articulate sounds be conveyed overa wire by means of an electrictelephone, thecircuit maybe interrupted fora considerable portion of thetime without interfering with or disturbing conversation, provided thatno oneinterval of interruption is of sufficient duration to be noticedby the ear, for example, one one-hundredth of a second 0r thereabout.Taking advantage of this fact or principle I have invented a method andapparatus by which several telephonic conversations can be carried onsimultaneously over one and the same line wire, or over one and the samepair of line wires in' metallic circuit. The method consists in talkingsimultaneously into each of several transmitting telephones andmeanwhile successively making and breaking a circuit over a common linewire, or pair of line wires in metal- 3 5 lie circuit, between each ofsaid transmitting telephones and its respective receiver at the otherend of the line, so that while the circuit is established between one ofsaid transmitters and its receiver at the other end of 40 the line oversaid common line wire, or pair of line wires in metallic circuit, it isbroken between the other transmitters and their respective receivers atthe other end of the line, with such rapidity that the human car willnot take notice of the interruption or mutilations of the soundsreceived at the receivers due to the interruptions of the currentssuccessively established, between the transmitters and theirrespectivereceivers at the other end of the line.

Broadly stated apparatus for practicing the invention consistsessentially of line wire, either single and grounded or double andadapted to be used in metallic circuit, two telephones at each end ofsaid line wire or wires, a switch at each end of said line wire or wiresadapted to make and break the circuit between said line wire or wiresand the telephones at the same end successively, and mechanism forvibrating said switches eon- 6o tinuously, rapidly and synchronously. Bysuch apparatus multiple conversation may be had intelligently over asingle circuit, either grounded or metallic; butin order to practice theinvention commercially, or to arrange for two simultaneous independentconversations over the same circuit, neither conversation to bedisturbed by or to disturb the other, and neither conversation to bedisturbed by the switching mechanism, I make use of details ofconstruction herein set forth, which form subordinate features of myinvention.

In the drawings,-Figure 1 represents in diagram a grounded telephonecircuit embodying my invention, with two complete sets of telephoneapparatus at each end. I Fig. 2 represents a metallic circuit embodyingthe invention with two telephones at each end, each telephone servingboth as a transmittingand receiving telephone. Fig. 3 represets a.single wire or grounded circuit with three telephones at each end. Fig.4 represents a metallic circuit embodying. theinvention with details ofconstruction, as mentioned above, to prevent disturbance between twoconversations or from the switching meehanism. Fig. 5 differs from Fig.4 by showing the synchronizing mechanism in grounded wires branchingfrom one of the wires of the metallic circuit, instead of showing it inan 0 independent circuit. Fig. 6 represents the perfected invention asembodied in two metallic circuits. Fig. 7 is a plan view of theswitching mechanism.

The same letters in the different figures in- 5 dicate like parts, andnumerals added to the letters have reference to the situations of likeparts. Complete telephone sets are shown in but one of the figures, butit will be readily understood that the telephones shown in the rec otherfigures represent or may represent telephone sets.

p and p";

In Fig. 1, L is a line wire common to all the telephones. T and T aretelephone sets at one end of said line wire, each consisting of atransmitting telephone, a battery, an induction coil, and a receivingtelephone as or dinarily used and as conventionally shown. T and T aretelephone sets at the other end of the said line. S is a switch at oneend of said line, consisting of avibrating reed o and contact-plates 1013 S is a similar switch at the other end of the line consisting ofvibrating reed o and contact-plates p p. The secondaries of theinduction coils of telephone sets T, T T and T are connectedrespectively with contact-plates p p 12 19 When the reeds o and "U2 arein contact with contact-plates-p and p a telephone circuit isestablished between telephone sets T and T and broken between T and Tand when they are in contact with contact-plates p and p a telephoniccircuit is established between telephone sets T and T and broken betweenT and T And if thereeds are vibrated at the rate of about one hundredtimes per second, continuous telephonic conversation can be carried onbetween T and T and at the same time between T and T neitherconversation interfering with the other.

Any suitable mechanism or mechanisms may be employed within myinvention, broadly considered, for shifting the two switchessynchronously. I11 the drawings I show the two reeds as the armatures oftwo polarized relays operated by a common alternating current dynamomachine. Thus I) is the dynamo, e e the polarized magnets having reed ofor an armature, and e and e are the polarized magnets having reed o foran armature, while w is the conducting wire of the synchronizing system.

In Fig. 2 where the invention is'represented as embodied in apparatusemploying metallic.

circuits single telephonesare shown instead of telephone sets, and theconstruction and arrangement of apparatus is such that tele' phones Tand T may alternately be connected and disconnected in metallic circuitand so also telephones T and T L and L are two line wires forming, whenconnections are made as directed, the main part of a metallic circuit. Sand S are switches placed re spectively at the two ends of the metalliccircuit and synchronously operated by a dynamo and polarized magnets asbefore described. The vibrating reed of each switch, 0 or '0 carries twocontact-points insulated from each other, 0 and 0 being attached to read4), and c and 0 being attached to read 11 Line L terminates incontact-points c and c and line L terminates in contact points 0 and 0Each contact-point vibrates over two contactplates, 0 over 13 and p; 0over 19 and p; 0 over 13 and 19 0 over 19 and 19 Telephone T isconnected up between contact-plates p and p telephone T betweencontact-plates telephone T between contactplates 13 and 19"; andtelephone T between contact-plates p and 19 When contactpoints 0 and care in contact with contact plates 19 and 19*, contact points 0 and 0will be in contact with contact-plates p and p and there is a metallictelephone circuit as follows: from telephone T to contact-plate p,contact-point 0, Wire L, contact-point 0 contact-plate p telephone Tcontact-plate 13", contact-point 0 wire L contact-point 0 contact-platep back to telephone'l". The other or alternate circuit is obvious.

In Fig. 3 hand telephones are shown as taking the place of the telephonesets of Fig. 1, three being shown at each end of the circuit. There areat each end an equal number of contact-plates, 7) p and 19 correspondingto telephones T T and T at one end of the line wire, and 19 19 pcorresponding to telephones T T T at the other end. The circuits areobvious. The reeds should be vibrated at such rate as not to be absentfrom contact with anyone contact-plate for more than one one-hundredthof a second.

In Fig. i is shown in diagram an apparatus embodying the invention asadapted to commercial use. Two improvements upon the apparatus of thepreceding figures are represented. The first of these consists in thesubstitution for the vibrating reeds at each end ofthe circuit, of twoapproximately synchronoustuning forks, and in the employment with saidtuning forks of a dynamo whose currents are approximately synchronouswith the nor mal rate of vibration of the tuning forks. The arms of thetuning forks are made to do the office of continuously vibratingswitches, being set and kept in vibration by the electro-magnets shown,which receive impulses of current from the dynamo synchronous as near asmay be with the rate of vibration of the vibration of the tuning forks.The secondimprovement consists in the use of an inductive resistance inthe synchronizing circuit to prevent the noise of the dynamo from beingheard in the telephone circuits. Accordingly in'Fig. 4, S is a tuningfork, one arm of which carries a contact-point c that vibrates over andupon contact-plates p and 19 while the other arm carries a contact-pointc that vibrates over and upon contact-plates p and p and in like mannerS is a tuning fork at the other end of the metallic circuit L L havingthe same rate of vibration as the tuning fork S, and having at the endsof its arms contact points 0 and c to vibrate respectively overcontact-plates p p and 19 p The connections of the telephones with thesaid contact-plates are, as shown, such that, when the arms of thetuning forks open one of the telephones at the same end of the line asthe tuning fork is thrown upon the line, while its mate at the same endisdisconnected, but is itself disconnected while its said mate is thrownupon the line, when the arms of the tuning fork close upon each other.The magnets e e and e? e in the synpolarized. D

chronizing circuit 10 are not is the dynamo and R is an inductiveresistance in said synchronizing circuit, consisting of aMuirheadcondenser with an electromagnet on either side, substantially asdescribed in my Patent No. 485,279.

Fig. 5 shows the same arrangement of apparatus that is shown in Fig. 4,except that the inductive resistance R is placed in a synchronizingcircuit, b w, branching from one of the wires L of the metallic circuitinstead of an independent synchronizing circuit. In this case also asecond inductive resistance R is placed ina branch synchronizing circuit12 to at the other end of the telephone circuit. The dynamo machinethough shown in branch I) to may be in'either branch.

Fig. 6 represents the invention as embodied in two metallic circuitswith a single synchronizing circuit. Each circuit taken by itself is thesame as the circuit shown in Fig. 4.

Fig. 7 is a plan View of the switch mechanism as actually constructed.In Fig.7 A is the bed-plate, S is the tuning fork clamped in a bracket Bby screws, as shown; while 66 are electro-magnets supported in spectacleframes 0 C and adjustable two and from armatures a a, mounted upon butinsulated from the arm of thertuning fork by screws b, 1), workingthrough posts at d, and screws 4% n, as shown. F is a sliding plate ofinsulating material held by means of slot and screw g between ways it hat the front of the bed-plate A and having an adjustment to and from thefront ends of the tuning fork by means of screws 2' 'i. The said slidingplate F at each end carries a block G of insulating material having atoand fro motion by means of screwj and spring It in ways I, also ofinsulating material, which are screwed to the bed-plate. The blocks G- Gcarry each two contact-plates p p which are separated by a thin micaplate m. H H are rodsadjustable lengthwise on the front ends of the armsof the tuning fork and carry each a contactpoint 0 which by thevibrations of the tuning fork is given a rapid reciprocating motion overthe contact-plates p p and mica plate m. The connections aresufficiently indicated in the diagrams. v

I claim- 1. Theherein described method of carrying on multipletelephonic conversation, or several telephonic conversations at the sametime over the same line wire, or over the same pair of line wires inmetallic circuit, consisting in talking into each of two or moretransmitting telephones and meanwhile successively making and breaking acircuit between said transmitting telephones and their respectivereceivers at the opposite end of the line, so that while a circuit isestablished between one of said transmitters and its receiver at theopposite end of the line, the circuit is broken between the othertransmitter and its correspondin g receiver, or between the othertransmitters and their corresponding receiver's,

with such rapidity that the human ear will not notice the interruptionsor mutilations of sounds received at the receivers due to theinterruption of the currents successively established between thetransmitters and their respective receivers.

2.' The combination with a telephone circuit, whether grounded ormetallic, and two telephones or telephone sets at each end of saidtelephone circuit, of two vibrating switches, one also at each end ofsaid circuit adapted to connect and disconnect therewith each of saidtelephones or telephone sets at the same end at every vibration, andmechanism for vibrating said switches synchronously and with a rapidity,substantially as described.

3. The combination with line wires adapted to housed in metallictelephone circuit or circuits, telephones or telephone sets at each endof each pair of said line wires, and switches at each end of each pairof line wires, each said switch being adapted to connect and disconnecttwo of said telephones or telephone sets with a pair of said line wires,of a synchronizing circuit, either independent or branching from saidtelephone circuits, and a dynamo machine and electro magnets in saidsynchronizing circuit adapted to operate and synchronize said switches,said switches being vibrated with a rapidity substantially as described.

4. The combination with line wires adapted to be used in metallictelephone circuit or circuits, telephones or telephone sets at each endof each pair of said line wires, and switches at each end of each pairof line wires, each said switch being adapted to connect and disconnecttwo of said telephones or telephone sets with a pair of said line wires,of a synchronizing circuit, either independent or branching fromsaidtelephone circuits, eleetro magnets and a dynamo machine in saidsynchronizing circuit for operating with the rapidity indicated andsynchronizing said switches, and an inductive resistance in saidsynchronizing circuit, substantially as described.

5. A metallic telephone circuit or circuits, tuning forks having auniform rate of vibration of a rapidity such as specified, therebeingone of said tuning forks at each end of each of said circuits andthe two wires of each of said circuits terminating each at each end inan insulated contact-point carried by a separate arm of the tuning forkat the same end, and telephones or telephone sets in pairs andcorresponding contact-plates in double pairs at each end of each of saidcircuits, the said insulated contact-points on said tuning IIC forksbeing adapted to vibrate each over two of said contact-plates, incombination with a synchronizing circuit either independent or branchingfrom one of said telephone circuits containing electro-magnets, one foreach arm of said tuning forks, and a dynamo machine adapted to sendimpulses corresponding to the rate of vibration of saidiuning forks,substantially as described.

6. A metallic telephone circuit or circuits, tuning forks having auniform rate of vibration of a rapidity such as specified, there beingone of said tuning forks at each end of each of said circuits and thetwo wires of each of said circuits terminating each at each end in aninsulated contact-point carried by a separate arm of the tuning forkatthe same end, and telephones or telephone sets inpairs andcorresponding double pairs of contactplates at each end. of each of saidcircuits, the said insulated contact-points on said tuning forks beingadapted to vibrate each over two of said contact-plates, in combinationwith a synchronizing circuit, either independent or branching from oneof said telephone circuits, containing electro-magnets, one for each armof said tuning forks, a dynamo machine adapted to send impulsescorresponding to the rate of vibration of said tuning forks, and aninductive resistance, substantially as described.

7. The combination with a metallic telephone circuit, two pairs oftelephones or telephone sets, one of said pairs at either end of saidtelephone circuit, two tuning forks of the same rate of vibration suchas hereinbefore specified, one of them also at either end of saidtelephone circuit and suitable contacts whereby the telephones ortelephone sets at either end of said circuit may be connected anddisconnected therewith by the vibrations of the said tuning fork at thesame end, of a synchronizing circuit containing electro-magnets and adynamo machine adapted to send impulses corresponding to the rate ofvibration of said tuning forks, substantially as described.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribing witnesses, this 21st day of November, 1893.

WILLIAM W. JACQUES.

Witnesses:

B. L. RUGGLES, GEO. WILLIS PIERCE.

